SeattleGS400

iTrader: (1)

I'm looking to change my coolant in my GS400 (1UZ-FE V8 engine), and I was wondering where the the heater water valve was, and how I could open it up to bleed the cooling system? Is it: 1) a bolted on item? or 2) do I just need to turn climate control to the hottest setting before changing the coolant, then switching it back to a more moderate temperature after changing the coolant? I know on some other car models, it's just a bolt on the top of the engine block that you remove when refilling the coolant, and it allows air bubbles to be bled out of the cooling system, then you replace it when you're done refilling the coolant

The heater water valve is mentioned in step 2-C in the '99 Lexus factory service manual procedure. Should I even worry about it? See below (if the *.pdf attachment doesn't work):

REPLACEMENT
1. DRAIN ENGINE COOLANT
(a) Remove the radiator cap.
CAUTION:
To avoid the danger of being burned, do not remove the radiator cap while the engine and radiator are still hot, as fluid and steam can be blown out under pressure.
(b) Loosen the radiator drain plug (on the left side of the radiator lower tank) and engine drain plug (on the cylinder block), and drain the coolant.
(c) Close the 3 drain plugs.
Torque: 24.5 N·m (250 kgf·cm, 18 ft·lbf) for engine

2. FILL WITH ENGINE COOLANT
(a) Slowly fill the system with coolant.
* Use a good brand of ethylene–glycol base coolant and mix it according to the manufacturer’s directions.
Grade:
”TOYOTA LONG LIFE Antifreeze Coolant” or equivalent

Using coolant which includes more than 50 % ethylene–glycol (but not more than 70 %) is recommended.
NOTICE:

Do not use an alcohol type coolant.

The coolant should be mixed with demineralized water or distilled water.
Capacity: 9.3 liters (9.8 US qts, 8.2 lmp. qts)
(b) Install the radiator cap.
(c) Bleed the cooling system.
(1) Start the engine , and open the heater water valve.
(2) Maintain the engine speed at 2,000 – 2,500 rpm, and warm up the engine.
(d) Stop the engine, and wait until the engine coolant cools down.
(e) Refill the radiator reservoir with coolant until it reaches the
”FULL” line.

3. CHECK FOR ENGINE COOLANT LEAKS

VVT-i

You don't need to remove or disconnect the heater valve hose.
To fill it up, you have to remove the engine cover.
On top of the throttle body( GS & LS 400) you will see 10mm hex bolt that screw on top of the TB.
Remove that bolt and remove the radiator cap. I've found the plastic water bottle to be a perfect funnel to fill it up. I cut the bottom part of water bottle and shape off the thread so it will fit the filler hole, then turn it up side down to fill the coolant.
Then fill the coolant until the coolant come out of the radiator. Install the 10mm bolt back on.
Start the engine and turnt the heater to Max Hot. Let the engine idle while you fill the coolant from the radiator.
After the engine reach normal operating temp. put the radiator cap back on and rev the engine to about 2500 rpm for about 10 minutes. Shut off the engine and let the car cool down and then fill the radiator and resevior.

SeattleGS400

iTrader: (1)

Thanks for the info--that's exactly what I was looking to know.